The researchers, whose findings were reported in Pediatrics, found that, in general, preterm babies tend to have more difficulty with complex language skills as they grow older, such as reading or writing complex sentence structures -- at least, up to age 12.

The study, which pooled data from 17 previous studies, looked at 1,529 premature children born before the 37th week of pregnancy, and 945 full-term children.

It does not mean that premature babies are doomed to long-term language problems. But they may have a tougher time than their peers do later on in school.

"While growing up, preterm-born children have increasing difficulties with complex language function," wrote study leader Inge van Noort-van der Spek, at Erasmus Medical Center in Rotterdam, the Netherlands, and colleagues.

The study found that in early childhood, there were smaller differences between preterm and full-term children as far as simple language abilities, like basic vocabulary.

But between the ages of 3 and 12, the gap tended to widen when it came to complex language skills.

"This study confirms what is observed in the real-life clinical setting: preterm children are at higher risk of language problems, and as the language task becomes more demanding, the proportion of children with significant impairment also increases," said Thuy Mai Luu, a pediatrician at CHU Sainte-Justine and the University of Montreal in Canada who was not involved in the study.

In general, preterm children may have normal language skills at the age of 2, when the demands are low.

"However, a few years later, when language functions required to succeed in school are more complex, this is the time when problems may appear and limit the child in scholastic or social activities," Luu said.

In her own research, she has found that preterm children tend to "catch up" to their peers as far as basic language -- and brain imaging research suggests preemies can develop "compensatory" nerve connections related to simple language skills.

It's possible, though, that for complex language tasks, there is a limit to the brain's ability to compensate, she added.

"The take home message is to remain vigilant (about) language difficulties in the clinical setting," she said. SOURCE: bit.ly/GLtBly

(Reporting from New York by Amy Norton at Reuters Health; editing by Elaine Lies)

• A Permanent Economic Emergency